Create Tag

Define one tag on a knowledge base; use PUT on this path to declare several at once. Define a tag here, write its tagSlot on a document with PATCH /api/v2/knowledge/{knowledgeBaseId}/documents/{documentId}, then filter by its displayName on the document list or on search. Omit tagSlot to take the next free slot for the field type; a field type with no free slot left is a 400 naming it, since the remedy is a different type or a deleted definition rather than a retry. A tagSlot already taken, or a displayName already defined on this knowledge base, is a 409 naming which of the two to change. A workspace API key is rejected with 403; use a personal API key.

POST/api/v2/knowledge/{knowledgeBaseId}/tags

Authorization

apiKey
X-API-Key<token>

Your Sim API key, personal or workspace-scoped. Generate one under Settings, then API Keys. Operations that reject workspace keys say so in their own description.

In: header

Path Parameters

knowledgeBaseId*string

Unique knowledge base identifier.

Length1 <= length

Request Body

application/json

Workspace scope, display name, field type, and optional slot.

TypeScript Definitions

Use the request body type in TypeScript.

Response Body

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

curl -X POST "https://www.sim.ai/api/v2/knowledge/string/tags" \  -H "X-API-Key: YOUR_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "workspaceId": "a91c4b2e-6d3f-4e8a-b5c7-0d9e2f1a8c64",    "displayName": "category",    "fieldType": "text"  }'
{
  "data": {
    "id": "string",
    "displayName": "category",
    "tagSlot": "tag1",
    "fieldType": "text"
  }
}
{
  "error": {
    "code": "BAD_REQUEST",
    "message": "Invalid request"
  }
}
{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "API key required"
  }
}
{
  "error": {
    "code": "FORBIDDEN",
    "message": "Insufficient workspace permissions",
    "details": {
      "code": "INSUFFICIENT_WORKSPACE_ROLE"
    }
  }
}
{
  "error": {
    "code": "NOT_FOUND",
    "message": "Not found"
  }
}
{
  "error": {
    "code": "CONFLICT",
    "message": "Upload has already been completed"
  }
}
{
  "error": {
    "code": "PAYLOAD_TOO_LARGE",
    "message": "Request body is too large"
  }
}
{
  "error": {
    "code": "UNSUPPORTED_MEDIA_TYPE",
    "message": "Request body must be sent as application/json"
  }
}
{
  "error": {
    "code": "RATE_LIMITED",
    "message": "API rate limit exceeded",
    "details": {
      "retryAfter": "2026-01-01T00:00:30.000Z"
    }
  }
}
{
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "Internal server error"
  }
}
{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "message": "Service temporarily unavailable"
  }
}